Sewing-machine motor drive



A. T. MACE.

. SEWING MACHINE MOTORID'RIVE.

APPLICATION-FILED FEB. 17, 1921.

Patented Ma-y 30, 1922.

2 SHEETSSHEET 1- Juan 70a Jrrozzwzrs .A. T. MACE.

SEWING MACHINE MOTOR DRIVE. APPLICATION F|LED.FEB. 1'7, 1921.

Patented May 30,1922.

2 SHEETS-SHEET 2- UNITED STATES PATEN OFFICE.

ARTHUR '1. MACE, OF EAST CLEVELAND, OHIO, ASSIGNOR TO THE DOMESTIC ELEC- TRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

snwme-macm' Moron mam Patented Ma 30,1922.

Application iiled February 17, 1921. Serial No. 445,835.-

To all whom it may concern:

Be it known that I, ARTH R T. MACE, a citizen of the United States, residing at East Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Im rovement in Sewing-Machine Motor Drlves, of which the following is a full, clear, and exact description, reference being hadto the accompanying drawm s.

Ihis invention is directed to improvements in motor driven sewing machines and has particular reference to an arrangement of the mechanism within the head of the sewing machine wherein a motor may be located, which is adapted to drive the ma chine.

The general practice heretofore, 1n arranging the mechanism of a sewing machine to adapt a motor drive thereto, hasbeen to resort to the use-of, a series of reduction gears inaccessibly ositioned' within the standard of the sewlng machine. Such an arrangement is unsatisfactory in thatthe assembling, bearing and lubricating problems become quite involved, for a practical motorwhich would meet the requirements of such a drive requires the use of high speeds.

The essential objects of this invention,-

therefore include the arrangement of the driving mechanism of the machine in such a manner that the needle bar actuating means and the shuttle actuating means may be driven in. synchronism with a shaft driven by a motor mounted within the standard in the machine without the use of high speed reduction gears.

Morespecific objects include a simple arrangement of the driving mechanism and motor within the standard so that the machine may be manufactured as a complete unit with provision for a subsequent instal-v lation of a motor drive by the simple expedient of securing the motor to the machine by one removable holding element. One of the essential requirements of a practical adaptation of a motor drive to a sewing machine is that the machine-may be manufactured and assembled without necessitating the inclusion of additional expensive parts, and it has been the practice heretofore to alter the general character of the synchronizing mechanism within the sewing machine standard in such a manner that it was necessary to assemble the motor at the Referring to the drawings, Fig. 1 is a side elevation of the sewing machine with a part of the base, standard and needle supporting arm shown in cross section; while Fig. 2

is a cross sectional end elevation of the standard; Fig. 3 is a bottom plan view of the motor drive, and Fig. 4 is a transverse section of the standard substantially along the line 44 of Fig. 2. 1

Designating the I various parts by numerals, in Fig. 1 I have shown a motor 5,

mounted within the standard fi which is supported on the base 7 of the machine. A vertical synchronizing shaft, 8 having bevel gears 9 and 10 rigidly mounted near the ends thereof, is adapted to drive the needle bar actuating shaft 11, supported by the .arm 4 and the shuttle actuating shaft 12,

through the rigidly mounted gears 13 and 14, at a reduced speed. The synchronizing 'shaft 8 may be provided with an upper bearing 15 located within the standard near the topand integral therewith, while a similar bearing 16, integral with the standard and in alignment with bearing 15 may be 10- rated near the base. This shaft may be of sufficient length to provide an extending portion beyond the gear 10 as shown at 16, upon which, a large sheave 17 can be quickly and easily secured onthe lower end thereof,

which may be positioned to clear the bevel gear 14 and the shuttle actuating shaft 12.

One of the'problems heretofore in manufacturing motor driven sewing machines has been to produce a motor of suflicient compactness and durability that would be of such! size and shape as to permit ofits prac-. tical and economical installation within the standard of the machine, and have the requi- "site power to drive the sewing machine mechanism at any of the desired speeds. I'

have found that it is possible to construct a small motor with a circular casing that will meet these requirements and which can alsobe regulated by the usual foot control rheostat. Such a motor is shown as being positioned and supported within the lower enlarged part 6 of the standard and secured therein by means of a single screw 18 of a suitable size to engage the frame thereof and to retain it withits armature shaft in substantially vertical alignment with the synchronizing shaft 8. To insure the proper positioning of the motor when the screw 18 is tightened, I have provided acyllndrlcal finished surface 19 on the lower 'inside of the enlarged part of the standard of slightly larger diameter than the motor, which forms an adequate support therefor, and which is in suflicient contact with the outside surfaces thereof to prevent any vibration that would tend to loosen the screw 18. This surface is likewise in such position on the standard that it may be quickly and economically machined in the process of manufacture, while the screw 18 is positioned to be accessible on the outside of the standard and to oppose the pull on the motor during operation of the machine. On the lower end of the armature shaft I have shown a small driving sheave 20 which may 7 be also properly aligned with the sheave 17 when the screw 18 engages the motor frame. To obtain the proper operating speed of the synchronizing shaft 8, I have illustrated a synchronizing shaft.

preferred means consisting of an endless flexible belt 21 passing around the sheaves 17 and 20 on the synchronizing and armature shafts respectively which drives the former at a speed reduction which is inversely proportional to the ratio of the sheave diameters.

It is to be readily seen that in the arrange ment as shown the motor may be detached from the standard by removing the sheave 17 from the end of the shaft 8 and the screw 18 which holds the motor, and that the motor may then be moved downwardly out of the standard without encountering any difficulties of loosening the motor and rheostat wires which lead thereto from the open under side of the machine.

If desired, the lubricatingcup 23 on the lower part of the motor may be refilled from the under side of the base of the motor while access to the upper lubricating cup 24 may be had through the opening 25 in the Wall of the standard. Furthermore it is to be understood that the mechanism in the machine may be assembled and tested independent of the motor assembly and that any inaccuracies which may occur in the boring of the standard or the finishing of the motor frame will not affect the efiicient installation of the motor drive. Also it is to be seen that the only additional mechanism required for adapting the machine to a motor drive is a sheave secured to the lower end of the Likewise it' is to be understood that any variations which may occur in the assembling of the mechanism within the standard, will not complicate the assembly of the motor therein, as the variations of the. distance between the centers or the synchronizing shaft 8 and the armature shaft, will not affect the driving efficiency of the flexible belt.

By arranging the driving mechanism as above described and by the use of a motor of the proper design, I am enabled to overcome the difficulties encountered through the limitations of the standard sewing machine heads when placing a motor drive therein. Also by locating the motor near the base of the standard it is possible for me to use driving sheaves of sufficient size to obtain the proper speed reduction without resorting to the use'of troublesome reduction gears and the like. A still further advantage in the use of the above described mechanism is that the operating parts are easily accessible from the under open side of the machine.

Having thus described my invention, I claim 1. In a motor driven sewing machine, the combination of needle bar and shuttle actuating members having a vertical drive shaft geared to said actuating members so as to cause them to move at less speed than thedrive shaft, a hollow standard having provision for a motor, a motor removably mounted within such standard with its armature shaft substantially parallel with the drive shaft, and driving means connecting the armature shaftv with the drive shaft including a sheave mounted on the drive shaft projecting beneath the motor and removable whereby said driving means may be removed without disturbing the synchronous opersaid base, a motor having its shaft projecting below the hollow standard and supported thereby, a vertical shaft extending along the side of the motor adapted to drive substantially parallel shuttle and needle bar actuating shafts in synchronism, and driving means located below the shuttle shaft connecting the armature shaft of the motor and the drive shaft of the machine.

3. In a sewing machine having a plurality of actuating shafts within suitable housing members interconnected by a hollow stand-' ard adapted to support a motor therein at the lower end thereof, a drive shaft therefor housed by the standard, an electric motor positioned within the lower portion of the standard, and means connecting said drive shaft with the motor comprising a small sheave on the motor shaft and a large sheave on the drive shaft positioned to lie within a common plane, said sheaves being connected by a flexible driving means.

4. In a motor driven sewing machine, the combination of needle bar and shuttle actuating members having a vertical drive shaft geared to said actuating members so as to cause them to move at less speed than the drive shaft, a hollow standard having internal surfaces near the base thereof conforming to the outer surface of a motor mounted therein, the armature shaft of said motor being substantially parallel with the drive shaft, and driving means positioned to lie within a commonplane and connecting the armature shaft with the drive shaft.

5. In a motor driven sewing machine having a hollow horizontal arm, housingneedle bar actuating means, a base, a hollow standard supporting said arm and connected to said base, a motor protruding from within the lower portion of the hollow standard, a vertical shaft extending along the side of the motor adapted to drive substantially parallel shuttle and needle bar actuating shafts in synchronism at a lower speed than the speed of the drive shaft and speed reduction means located in a common plane below the shuttle shaft connecting the armature shaft of the motor and the drive shaft.

6. In a sewing machine having a plurality of actuating shafts within suitable housin members interconnected. by a hollow standard adapted to support a motor at the lower end, reduction gears rigidly mounted on said shafts, a drive shaft therefor housed by the standard, pinions mounted on said latter shaft meshing with said gears, an electric motor positioned within the standard, and speed reduction means connecting said drive shaft with the motor comprising a small sheave on the motor shaft and a large sheave on the drive shaft positioned to lie within a common plane and connected by a flexible endless belt.

7. In a motor driven sewing machine having a hollow horizontal arm, housing needle bar actuating means, a base, a hollow standard supporting said arm and connected to said base, a motor protruding from within the lower portion of the hollow standard and supported thereby, vertical connecting means extending along the side of the motor adapted to drive substantially pan allel shuttle and needle-bar actuating shafts in synchronism and driving means located below the shuttle shaft connecting the armature shaft of the motor and the driving means of the machine.

8. In a sewing machine having a plurality of actuating shafts within suitable housing members interconnected by a hollow standard adapted to support a motor therein at the lower end thereof, driving means therefor housed by the standard, an electric motor positioned within the, lower portion of the standard, and-means connecting said driving means with the motor comprising a small sheave on the motor shaft and a large sheave on the driving means positioned to lie within a common plane, said sheaves being connected by a flexible driving means.

9. In a motor driven sewing machine having a hollow horizontal arm, housing needle bar actuating means, a base, a hollow standard supporting said arm and connected to said base, a motor protruding from within the lower portion of the hollow standard, driving means extending along the side of the motor adapted to drive substantially parallel shuttle and needle bar actuating shafts in synchronism at a lower speed than the speed of the driving means, and speed reduction means located in a common plane below the shuttle shaft connecting the armature shaft of the motor and the driving means.

10. In a motor driven sewing machine, the combination of needle bar and shuttle actuating members, having a vertical drive shaft geared to said actuating members so as to cause them to move at less speed than the drive shaft, a hollow standard having provision for a motor, a motor removably mounted within such standard with its armature shaft non-aligned therewith and substantially parallel with the drive shaft, drivprising a surface within the standard adapt ed to bear upon the perimeter of the motor casing and securing means opposing the driving pull on the motor whereby one end of the motor casing may compressively bear upon said surface.

12. In a motor driven sewing machine, the combination of a needle bar and shuttle actuating members having practical driving means geared thereto, a hollow standard housing the vertical driving means and having a support for a motor, said sup rt comprising a surface within the stan ard adapted to bear upon the periphery of the motor casing, and a removable member carried by the standard and projecting into a recess in the motor casing whereby the torque exerted on the casing when the motor is operated causes the casing to bear upon the surface of the supportv to hold the motor firmly in position. 

